1. Field of the Invention
Down hole forward and back scuttling tool.
2. Description of the Prior Art
In oil field operations, the lower portion of an oil well bore hole may be enlarged to define an elongate cavity by rotating a transversely expandable reamer that is secured to the lower end of a power driven drill string. Cuttings from the reaming operations drop downwardly to rest on the bottom of the cavity. Prior to a perforated liner being extended into the cavity, and the cavity filled with gravel to facilitate the production of oil, the cuttings should be removed from the cavity. In the past, the removal of the cuttings from a cavity has presented time consuming difficulties.
The primary purpose in devising the present invention is to supply a tool that may be interposed between the lower end of a drill string and the upper end of the reamer to serve not only as a torque transmitting element, but to permit the flow of fluid under pressure through either a first or second path.
The fluid, which will normally be drilling mud, flows through the first path when the drill string is rotating the expandable reamer to form the elongate cavity. Fluid as it flows through the first path, moves downwardly in a longitudinal passage in the drill string to pass through the interior of the tool and discharge through one or more openings in the reamer, and then flow upwardly from the cavity through an annulus shaped space defined between the drill string and side wall of the bore hole to the ground surface.
The fluid when it flows through a second path moves downwardly through the annulus space between the drill string and side wall of the bore hole to enter the cavity, with the fluid after it enters the cavity being in a turbulent condition, and in this condition lifting cuttings from the bottom of the cavity to entrain the cuttings with the fluid. The fluid with entrained cuttings now enters a port or ports in the reamer to flow upwardly therethrough into the interior of the tool, and from the tool through a check valve associated therewith into the interior of the longitudinal passage in the drill string. The fluid with entrained cuttings flows through the longitudinal passage in the drill string to the ground surface where the cuttings are separated from the fluid by conventional means, such as settling or the like. The check valve prevents cuttings carried into the longitudinal passage of the drill string to drop downwardly by gravity to return to the cavity in which they were initially disposed.